The invention relates generally to an adhesive testing method and a testing assembly for performing the test method.
ASTM D1002 is a method commonly performed to measure the shear strength of adhesives that are used to bond metals. ASTM D1002 is similar to ASTM D3163 and is for adhesives that bond rigid plastic substrates. ASTM D3164 provides a method for testing the strength of plastic adhesives that are used to bond both plastic and metal substrates. These methods use a single lap joint (lap shear) specimen to determine the shear strength of the adhesive tested.
In general, the shear area is first calculated in, for example, square inches or square centimeters. The specimen is loaded into the grips of a tensile test machine and force is applied at a controlled rate to pull the joint until the specimen breaks apart. The tensile machine records the maximum force and the type of failure. There are a number of other ASTM methods for measuring adhesive shear strength, including tests that measure creep properties and the effects of temperature on failure. However, while these tests provide useful information they have not been found to be fully satisfactory in measuring the ability of an adhesive to properly secure a carpet or tile to an existing substrate.
Accordingly, it is an object of the invention to provide an improved method and apparatus for performing the method, to overcome the inadequacies and limitations of the prior art.